[theora] Poor encoding quality with etheora and aspect ratio problem

[Ribamar Santarosa de Sousa]

On Sun, Mar 9, 2008 at 2:21 PM, Manuel Dahmen <manuel.dahmen at gmail.com> wrote:
> On Sun, 9 Mar 2008 14:04:49 +0100
>
> Manuel Dahmen <manuel.dahmen at gmail.com> wrote:
>
>
>
> > On Sun, 9 Mar 2008 04:00:14 -0300
>  > "Ribamar Santarosa de Sousa" <ribamar.santarosa at gmail.com> wrote:
>  >
>  > > Manuel,
>  > >
>  > > can you test the version in
>  > > http://svn.xiph.org/experimental/ribamar/etheora/ ?
>  > >
>  > > The final resolution (Fr) shown by  the mplayer output is the video
>  > > frame resolution (fr) multiplied by the Aspect ratio (Ar):
>  > >
>  > > Fr = fr * Ar. This should be the 16:9 or 4:3 final visual you
>  > > probably expected to see shown by  the mplayer output. Etheora was
>  > > doing:
>  > >
>  > > Ar = fr, what led to problems. Now etheora does:
>  > >
>  > > Ar = Fr / fr,  which I expect to led to the correct values, but I
>  > > may have missed any test. Can you see (and report) if now it's
>  > > working?
>  >
>  >
>  > I ran some tests this morning with the new version.
>  >
>  > What I was doing  before in my source code is adding this code between
>  > enc_setup and enc_start:
>  >       ec->ti.width=width;
>  >       ec->ti.height=height;
>  >       ec->ti.frame_width=width;
>  >       ec->ti.frame_height=height;
>  >       ec->ti.aspect_numerator=1;
>  >       ec->ti.aspect_denominator=1;
>  >       // So I keep the original resolution when playing, with square
>  >       //pixel ratio (for drawing shapes in processing.org).
>  >
>  > Here is mplayer output (file are named
>  > "movie-{ASPECT_CONSTANT}-WIDTHxHEIGHT" where width and height are the
>  > values passed in etheora_enc_setup. I commented these lines for the
>  > tests below. I put the resulting videos here :
>  > http://poux.be/tmp/video__test21/

Manuel,

can you please diff your etheora.c against
http://svn.xiph.org/experimental/ribamar/etheora/src/etheora.c ? I've
used the same parameters  you said to have tested, but the results
seem to be correct:

NORMAL:

640x480
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
VO: [xv] 640x480 => 640x480 Planar YV12

400x400
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
VO: [xv] 400x400 => 534x400 Planar YV12


WIDE:

640x480
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
VO: [xv] 640x480 => 854x480 Planar YV12

400x400
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
VO: [xv] 400x400 => 712x400 Planar YV12


PRESERVE:

640x480
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
VO: [xv] 640x480 => 640x480 Planar YV12


400x400
Movie-Aspect is 1.00:1 - prescaling to correct movie aspect.
VO: [xv] 400x400 => 400x400 Planar YV12

I got these results with the encoder example in
http://svn.xiph.org/experimental/ribamar/etheora/examples/encoder-example.c


Regards,
Ribamar




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